[unreadable] [unreadable] Exposure to diesel exhaust, a significant source of particulate matter (PM) in urban residential environments, adversely effects respiratory health of asthmatics and augments allergic sensitization to allergens. Yet much remains unknown about which aspects of diesel exposure are driving the observed health effects, the effect of diesel exhaust exposure in combination with other asthma triggers, and whether any of the effects of diesel are modifiable on an individual basis. The Michigan Center for the Environment and Children's Health (MCECH) recently conducted an integrated ambient PM exposure assessment, health effects epidemiologic study, and home intervention to reduce indoor allergens among asthmatic children in Detroit. Fluctuations in lung function associated with PM2.5 or PM10 exposure were more prominent in children who were allergic to cockroach compared to those who were not allergic. These data suggest a model in which PM, specifically that derived from diesel exhaust, and indoor allergen exposures interact synergistically to increase pulmonary inflammation in asthmatic patients. To test this hypothesis, the investigators propose these specific aims: [unreadable] 1) Determine whether the fraction of ambient PM arising from diesel exhaust determines pollution-related respiratory health effects in children with asthma in an inner-city environment. Statistical associations between ambient elemental carbon (EC), a marker for diesel exhaust, and acute respiratory outcomes (lung function, symptoms, bronchodilator use, acute care visits) will be investigated in children with asthma. [unreadable] 2) Determine the potential interactions between the effects of ambient diesel exhaust (as traced by EC) and exposure to allergens and environmental tobacco smoke (lETS). Interactive effects between EC and household exposure to indoor allergens, and ETS exposure, on health status will be investigated in children with asthma. [unreadable] 3) Determine the causal relationship between indoor allergen exposure and heightened sensitivity to air pollutants by performing an intervention designed to reduce indoor allergen exposure. A new integrated health effects study and prospective randomized trial of home environmental intervention will be conducted with extensive spatial and temporal assessment of ambient diesel exposure, assessed by EC concentration and ultrafine particle number, and health outcomes. The investigators will compare the acute air pollutant-associated fluctuations in asthma health status in the intervention group to that in a control group. They will also investigate associations between exhaled hydrogen a biomarker of asthma activity, and diesel exhaust exposure. [unreadable] [unreadable] [unreadable]